Warm & Natural gets stiff even at 1.5" spacing on the quilting lines. You really need to do pretty minimal quilting -- which isn't ideal for frequent washing -- in order to get it soft enough. I switched to Warm & Plush so I could quilt closer than 2" for baby quilts.
That said, in order to get the elephant to stand out, using a single layer of W&N with no trapunto, I would quilt the background in a pale grey 50wt cotton thread like Aurifil #2846 (Iceberg). Then, I would switch to a trilobal polyester for the elephant like Superior Magnifico (40/2) #2092 (Ming Dynasty). And maybe also some Superior Magnifico #2096 (Zesty Lime). The dull grey cotton will recede more into the background while the shiny trilobal poly will make the elephant stand out. I'd maybe outline the elephant & quilt large, overlapping circles within it (little ones love puffy circles in the quilting!). For the background, I'd do something simple & more linear like crosshatching or oversized ribbon candy or such. I'd probably aim for 3" spacing for the background & 2.5-3" spacing for the elephant. If durability is more important, I would keep everything to 2" spacing as that will hold up better in the wash and with the daily wear-and-tear that kids put on their most beloved little quilts.
Oh... and SUPER cute quilt! Someone whose name begins with "E" is going to be one lucky little man!
